Melioidosis is endemic in Southeast Asia and tropical Australia with varying clinical features from benign skin lesions to fatal septicaemia. Imaging plays an important role in evaluation of the melioid liver abscesses. A 45-year-old man with underlying diabetes presented with fever and lethargy for 2 weeks and abdominal pain for 2 days. His liver was enlarged on examination. Blood investigations revealed mild leucocytosis and raised liver enzymes. Ultrasound showed multiple multiloculated hypoechoic lesions throughout the liver and spleen. CT of abdomen confirmed that some liver lesions were made up of asymmetric locules of varying sizes (honeycomb sign), while others had hypodense centre with small symmetric peripheral locules in radial fashion (necklace sign). Blood culture was positive for Burkholderia pseudomallei He was subsequently treated with ceftazidime for a month followed by oral trimethoprim-sulfamethoxazole for 3 months. Follow-up CT of abdomen a month after diagnosis and treatment showed resolving hepatic and splenic lesions.
Burkholderia pseudomallei causes a potentially fatal infection called melioidosis. We have developed a nonfluorescent, colorimetric in situ hybridization assay using a specific probe to target 16s rRNA of B. pseudomallei in formalin-fixed, paraffin-embedded infected tissues for diagnostic purposes and to study infectious disease pathology. A 63-base pair DNA probe was synthesized and labeled with digoxigenin by PCR. Probe specificity was confirmed by BLAST analysis and by testing on appropriate microbial controls. The in situ hybridization assay was specifically and consistently positive for B. pseudomallei, showing strongly and crisply stained, single bacillus and bacilli clusters in mainly inflamed tissues in seven human acute melioidosis cases and experimentally infected mouse tissues. Intravascular and extravascular bacilli were detected in both intracellular and extracellular locations in various human organs, including lung, spleen, kidney, liver, bone marrow, and aortic mycotic aneurysm, particularly in the inflamed areas. Intravascular, intracellular bacteria in melioidosis have not been previously reported. Although the identity of infected intravascular leukocytes has to be confirmed, extravascular, intracellular bacilli appear to be found mainly within macrophages and neutrophils. Rarely, large intravascular, extracellular bacillary clusters/emboli could be detected in both human and mouse tissues. B. cepacia and non-Burkholderia pathogens (16 microbial species) all tested negative. Nonpathogenic B. thailandensis showed some cross-hybridization but signals were less intense. This in situ hybridization assay could be usefully adapted for B. pseudomallei identification in other clinical specimens such as pus and sputum.
Melioidosis is a protean disease which is endemic to Southeast Asia and northern Australia. Here, we report a case of infected aortic aneurysm due to Burkholderia pseudomallei in an immunocompetent man 6 months after a trip to northern Malaysia. This patient initially received inappropriate surgical and antibiotic treatment, leading to a peri-prosthetic aortic infection with lumbar spondylitis and contiguous psoas muscle abscess. This case highlights the difficulty of diagnosing melioidosis given its diverse clinical manifestations and the limits of routine microbiological methods to identify B. pseudomallei Melioidosis should be considered a possible diagnosis in individuals with unexplained fever subsequent to travel in an endemic area.
Two tsunami survivors from Banda Acheh, Sumatra, presented with pyrexia of unknown origin and a nonresolving left-sided empyema, respectively. Both children had mixed infections of tuberculosis and melioidosis; Salmonella typhi was also present in the second patient. Mixed infections are common late sequela complications in post-tsunami victims.
Titres of melioidosis haemagglutinating antibodies of 1/40 or more were found in 18 of 905 British, Australian, and New Zealand soldiers serving in West Malaysia. Previous mild unsuspected melioidosis seemed to be responsible for these positive titres, which were more common in men exposed to surface water at work and during recreation. This accords with the current view that soil and surface water is the normal habitat of Pseudomonas pseudomallei, the causal organism. Pyrexia of unknown origin after arriving in Malaysia was significantly more common in men with titres of 1/40 or more than in the remainder. It is suggested that mild melioidosis may present as pyrexia of unknown origin. Pyrexias of unknown origin should be investigated vigorously in patients who are in or who have visited endemic areas.
This is a report of the first recognized case of melioidosis in Nepal. Illness began 1 month after returning from Malaysia after a 1 y stay. The case highlights the importance of ascertaining the travel history in any patient with a suspected infectious disease in this age of global travel.
Melioidosis is an infectious disease caused by Burkholderia pseudomallei whose clinical diagnosis can be difficult due not only to its varied clinical presentation but also to the difficulties in the microbiological diagnosis.Thus, it may be necessary to use molecular techniques for its proper identification once it is suspected. There are few antibiotics available for the treatment of this disease, which must be used over a long period of time. Although it is known to be endemic in Thailand, Malaysia, Singapore, Vietnam, and Australia, in Colombia there are few reported cases. We describe a case of melioidosis in the northern region of Colombia. Additionally, we review its clinical characteristics and treatment and we describe the local epidemiology of this disease.
There are few data on paediatric melioidosis in endemic areas outside rural north-eastern Thailand and northern Australia. This study reports 16 culture-confirmed cases of melioidosis in children aged < or = 15 years seen between 1976 and 2005 at an urban teaching hospital in Kuala Lumpur, Malaysia. Seven (43.8%) patients had septicaemic melioidosis (with three known deaths) and nine (56.2%) had localised disease (one death). Eleven (68.8%) patients had underlying diseases, including five with haematological malignancies. Skin, soft tissue and lymph nodes were most commonly affected. There were no cases of parotitis or pharyngocervical disease (seen in Thailand), or encephalomyelitis (seen in Australia). The differences in disease seen in this study compared with the mostly rural patients described in previous studies might be owing to a different patient population in an urban environment. Septicaemic melioidosis has a high mortality, but localised disease has a good prognosis, and selected cases may be cured without the full recommended treatment regimen.
Melioidosis is an infectious disease caused by Burkholderia pseudomallei, a gram-negative intracellular bacillus. Tuberculosis, also an infectious disease, is caused by Mycobacterium tuberculosis, an acid fast bacillus. In both diseases, patients commonly present with fever and respiratory symptoms due to sepsis which might lead to respiratory failure or sudden death if left untreated. Not only are these two entities similar in clinical presentation, but the autopsy findings may mimic each other, giving rise to difficulties in determining the cause of death. We report a case of melioidosis and compare it to a typical case of miliary tuberculosis. Similarities between the cases on gross and histopathological examinations are discussed. In such circumstances, microbiological culture of bodily fluids and internal organs should be performed to ascertain the correct cause of death.
Melioidosis is a potentially deadly infection that can affect any organ system. Reports of melioidosis of the ENT/head and neck region are relatively uncommon. Four cases are presented: (i) parotid abscess evolving into necrotising fasciitis, (ii) acute sinusitis and parapharyngeal cellulitis resulting in upper airway obstruction, (iii) acute suppurative lymphadenitis (iv) and chronic suppurative otitis media causing meningoencephalitis. Three of the four cases are believed to be unique, as a literature review of melioidosis in ENT/head and neck is also presented. Some practical issues of management are also discussed. Not suspecting melioidosis does not change contemporary empirical broadspectrum antibiotic therapy. The value of suspicion or on confirmation of diagnosis lies in anticipating and planning for rapid change.
We present the case of a 24-year-old woman with acute septicemic melioidosis resulting from inhaled infective dust during a blast injury. With appropriate antibiotic treatment and supportive therapy in the ICU, the patient made an uneventful recovery.
We report a rare case of suppurative epididymo-orchitis caused by Pseudomonas pseudomallei in a 56-year-old male. This is a gram negative bacillus found mainly in tropical zones. Diagnosis was reached by culture of the organisms after drainage of the scrotal abscess, and the patient was treated by a course of oral chloramphenicol 500 mg qid for 6 months.
Previous reports of melioidosis in Sabah are reviewed and a detailed account of a case, presenting as prostatitis, in a 40-year-old British male is given. The history suggested that the organism, Pseudomonas pseudomallei, was transmitted by a fly which entered the eye. Diagnosis was delayed and treatment presented some difficulty, the organism being relatively insensitive to amplicillin and gentamicin. Co-trimoxazole was the most effective, followed by minocycline. Cure was eventually achieved and after four years the patient was fit and normal, except for sterility.
Central nervous system melioidosis is an unusual infection in humans. This article reports a case of melioidosis presenting as an acute spinal epidural abscess. A discussion of this case and its management together with a brief review of melioidosis of the central nervous system is presented.
This review briefly summarizes the geographical distribution and clinical impact of melioidosis, especially in the tropics. Burkholderia pseudomallei (a gram-negative bacterium) is the major causative agent for melioidosis, which is prevalent in Singapore, Malaysia, Thailand, Vietnam, and Northern Australia. Melioidosis patients are increasingly being recognized in other parts of the world. The bacteria are intrinsically resistant to many antimicrobial agents, but prolonged treatment, especially with combinations of antibiotics, may be effective. Despite therapy, the overall case fatality rate of septicemia in melioidosis remains significantly high. Intracellular survival of the bacteria within macrophages may progress to chronic infections, and about 10% of patients suffer relapses. In the coming decades, melioidosis will increasingly afflict travelers throughout many global regions. Clinicians managing travelers returning from the subtropics or tropics with severe pneumonia or septicemia should consider acute melioidosis as a differential diagnosis. Patients with open skin wounds, diabetes, or chronic renal disease are at higher risk for melioidosis and should avoid direct contact with soil and standing water in endemic regions. Furthermore, there are fears that B. pseudomallei may be used as a biological weapon. Technological advancements in molecular diagnostics and antibiotic therapy are improving the disease outcomes in endemic areas throughout Asia. Research and development efforts on vaccine candidates against melioidosis are ongoing.
Infectious diseases account for a third of all the deaths in the developing world. Achievements in understanding the basic microbiology, pathogenesis, host defenses and expanded epidemiology of infectious diseases have resulted in better management and reduced mortality. However, an emerging infectious disease, melioidosis, is becoming endemic in the tropical regions of the world and is spreading to non-endemic areas. This article highlights the current understanding of melioidosis including advances in diagnosis, treatment and prevention. Better understanding of melioidosis is essential, as it is life-threatening and if untreated, patients can succumb to it. Our sources include a literature review, information from international consensus meetings on melioidosis and ongoing discussions within the medical and scientific community.